mirror-linux/include
Yosry Ahmed 2d4d2b1cfb mm: zswap: add zswap_never_enabled()
Add zswap_never_enabled() to skip the xarray lookup in zswap_load() if
zswap was never enabled on the system.  It is implemented using static
branches for efficiency, as enabling zswap should be a rare event.  This
could shave some cycles off zswap_load() when CONFIG_ZSWAP is used but
zswap is never enabled.

However, the real motivation behind this patch is two-fold:
- Incoming large folio swapin work will need to fallback to order-0
  folios if zswap was ever enabled, because any part of the folio could be
  in zswap, until proper handling of large folios with zswap is added.

- A warning and recovery attempt will be added in a following change in
  case the above was not done incorrectly.  Zswap will fail the read if
  the folio is large and it was ever enabled.

Expose zswap_never_enabled() in the header for the swapin work to use
it later.

[yosryahmed@google.com: expose zswap_never_enabled() in the header]
  Link: https://lkml.kernel.org/r/Zmjf0Dr8s9xSW41X@google.com
Link: https://lkml.kernel.org/r/20240611024516.1375191-2-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:08 -07:00
..
acpi ACPI: EC: Evaluate orphan _REG under EC device 2024-06-13 11:28:54 +02:00
asm-generic syscalls: mmap(): use unsigned offset type consistently 2024-06-25 15:57:38 +02:00
clocksource
crypto
drm Short summary of fixes pull: 2024-05-27 13:47:14 +10:00
dt-bindings dt-bindings: net: dp8386x: Add MIT license along with GPL-2.0 2024-06-07 12:16:22 +01:00
keys
kunit
kvm
linux mm: zswap: add zswap_never_enabled() 2024-07-03 19:30:08 -07:00
math-emu
media
memory
misc
net netfilter pull request 24-06-27 2024-06-27 13:00:50 +02:00
pcmcia
ras mm/memory-failure: improve memory failure action_result messages 2024-07-03 19:29:57 -07:00
rdma
rv
scsi scsi: core: Introduce the BLIST_SKIP_IO_HINTS flag 2024-06-13 21:03:13 -04:00
soc
sound ALSA: dmaengine: Synchronize dma channel after drop() 2024-06-11 17:13:31 +01:00
target
trace tracing/net_sched: NULL pointer dereference in perf_trace_qdisc_reset() 2024-06-27 11:06:30 +02:00
uapi syscalls: fix compat_sys_io_pgetevents_time64 usage 2024-06-25 15:57:20 +02:00
ufs
vdso
video
xen